1. Field of the Invention
The present invention relates to a method for driving of a linear oscillating motor during reciprocating oscillation, and a linear oscillating motor.
2. Discussion of Background Information
A linear oscillating motor includes a fixed magnet (e.g., an electromagnet). A movable member, which includes a magnet (e.g., an electromagnet or a permanent magnet), is supported relative to the fixed magnet to freely oscillate. A detector detects various oscillation parameters (e.g., amplitude, velocity, acceleration, etc.) of the movable member. In response to the output of the detector, a controller applies current to a coil of the fixed magnet to control oscillation of the movable member.
As the movable member oscillates, it generates a generally sinusoidal induced voltage within a magnetic detection coil adjacent the movable member. The period of full oscillation is separated into two half-periods (defined by the points at which the induced voltage is zero) over which drive control occurs.
When the oscillation frequency is relatively high, a high performance controller must be used to control the drive current since control must be based on a period shorter than the half-period. Such high performance controllers are expensive, and increase the overall cost of the device.